1. Field of the Invention
The present invention relates to keypad assemblies and, particularly, to a keypad assembly used in an electronic device and to a portable electronic device, using the same.
2. Description of Related Art
With the development of wireless communication and information processing technologies, portable electronic devices, such as mobile telephones and personal digital assistants (PDAs), are now in widespread use. Such electronic devices allow consumers to enjoy high technology services, almost anytime and anywhere. A keypad assembly as an input terminal has been an indispensable member of a portable electronic device.
A typical keypad assembly being used in a portable electronic device includes a printed circuit board therein. Several fixed contact points are formed on the printed circuit board, and several dome switches are respectively disposed above the fixed contact points. The keypad usually includes a plurality of key buttons and a soft rubber base. The key buttons are fixed on the rubber base by adhesive. The rubber base is set above the printed circuit board, while the key buttons respectively correspond to the switches. In use, a key button is pressed down, and the rubber base is deformed accordingly. The rubber base presses a corresponding switch to touch a fixed contact point, so that an electronic signal is formed/generated. When the key button is released, it returns to its original state due to the elasticity of the rubber base.
Since miniaturization of the portable electronic device is desired, the space for fixing the keypad is limited. Therefore, the number of key buttons of the portable electronic device is also limited. In order to overcome this problem, each key button is desired to correspond to several operating functions, via, e.g., the pressing of particular key combinations and/or pressing the same key multiple times. However, the functions of the portable electronic device have increased dramatically, and each key button of the typical keypad assembly only corresponds to a dome switch. Therefore, the key button might need to be pressed several times to carry out a certain function, which brings inconvenience to the users. In addition, the elasticity of the rubber base gives the dome switch a poor tactile feel.
Therefore, a new keypad assembly is desired in order to overcome the above-described problems.